gtk:grid-attach (grid child left top &optional width height)

grid -- a gtk:grid widget
child -- a gtk:widget child widget to add
left -- an integer with the column number to attach the left side of child to
top -- an integer with the row number to attach the top side of child to
width -- an optional integer with the number of columns that child will span, the default is 1
height -- an optional integer with the number of rows that child will span, the default is 1

Adds a child widget to the grid. The position of the child widget is determined by the left and top arguments. The number of cells that the child widget will occupy is determined by the optional width and height arguments.